(Mogul) Goliath Edison Screw (GES) E40 BASE LED corn light, The large E40 "Mogul" base is used on street lights, and high-wattage lamps (such as a 100-/200-/300-watt/ 400watt) and many non-incandescent high-intensity discharge bulbs. In areas following the National Electrical Code, general-use lamps over 300 W cannot use an E26 base and instead use the E39 base, 300 W lamps may use either base. It is a minor differences in sizes between E40 base and E39 base, usually they are interchangeable